Field of the Invention
The invention relates to a virtualization technique of a computer system, and more particularly, relates to a system and a method for dynamically assigning virtual functions, and a management host thereof.
Description of Related Art
A computer system (e.g. a desktop or laptop computer) requires a bus to perform data transmission with a peripheral component. With the rapid development of serial communication technology, peripheral component interconnection express (PCIE) having the advantage of high transmission rate gradually replaces peripheral component interconnection (PCI) and becomes the dominant transmission interface for peripheral component.
In recent years, due to the rapid progress in the development of Internet, users have growing demands for information services, which imposes a heavier burden on the server. Therefore, in order to reduce costs and efficiently use the resources, server virtualization technology has gradually become the trend. In terms of the specification of PCIE, single root I/O virtualization (SR-IOV) is one effective solution for server virtualization. The SR-IOV technology allows a physical host (e.g. computer host) to assign multiple virtual functions (VF) to different virtual machines. However, the SR-IOV technology is limited and can only support one single physical host. In other words, multiple virtual machines in one physical host can use the virtual functions simultaneously, but the virtual functions cannot be assigned to the virtual machines in different physical hosts at the same time. By contrast thereto, the multi-root I/O virtualization (MR-IOV) technology can virtualize hardware resources to support multiple physical hosts. However, equipment that conforms to the SR-IOV technology is not completely compatible to the server architecture of the MR-IOV technology. As a result, the equipment conforming to the SR-IOV technology has low practicality. Hence, it is necessary to develop an effective virtual function assigning technique.